Figure 6-4.Types of respirators.TYPES OF RESPIRATORSYou should be familiar with three basic types ofrespirators: AIR-PURIFYING, SUPPLIED-AIR, andSELF-CONTAINED BREATHING APPARATUS(SCBA).The air-purifying respirators (views A through D,fig. 6-4) remove air contaminants by filtering orabsorbing them as the air passes through thecartridge. These respirators may be disposable orhave a disposable prefilter on a cartridge.The supplied-air respirator (fig. 6-5) is used wheninsufficient oxygen is present, when the contaminanthas no odor, or when the contaminant is of such highconcentration or toxicity that a cartridge filter isinadequate. This respirator is not used inimmediately dangerous to life or health situations(IDLH) areas. IDLH areas are those in which deathor6-10